In some amplifier applications it is desirable to reduce or limit the bandwidth of an amplifier or an amplifier stage for a reduction of noise. To this end, compensating capacitors can by applied which may couple an input of the amplifier stage to its output, for example. Such a compensation can also be called a Miller compensation.
An exemplary application where such low bandwidth amplifiers can be used is a linear voltage regulator. For example, in a low dropout regulator, LDO, a low gain bandwidth can be chosen to achieve a desired noise reduction. As usually no alternating signal is generated by such a structure, a small bandwidth does not present any drawback.
However, during startup of a capacitive compensated amplifier, the initial charging of the capacitance can lead to a slew rate limitation. In other words, a conventional amplifier with a capacitive compensating scheme can have a startup time in which it may not be fully functional.